Baron Victor von Frankenstein would have admired the bounty of body parts scientists crafted in the lab this year.

Lab-grown lumps of liver, bits of brain and clumps of heart, kidney and retinal cells can now mimic the functions of organs grown the old-fashioned way.

Scientists have no plans to assemble a monster, of course. Artificial organs may instead one day help repair or even replace a person’s damaged tissues. But that day is still many years away, says retinal cell researcher Robin Ali...